chapter_11.py 文件源码

def plot_silhouettes(X, y):
    cluster_labels = np.unique(y)
    n_clusters = cluster_labels.shape[0]
    silhouette_vals = silhouette_samples(X, y, metric='euclidean')
    y_ax_lower = 0
    y_ax_upper = 0
    yticks = []
    for i, c in enumerate(cluster_labels):
        c_silhouette_vals = silhouette_vals[y == c]
        c_silhouette_vals.sort()
        y_ax_upper += len(c_silhouette_vals)
        color = cm.jet(i / n_clusters)
        plt.barh(
            range(y_ax_lower, y_ax_upper),
            c_silhouette_vals,
            height=1.0,
            edgecolor='none',
            color=color,
        )
        yticks.append((y_ax_lower + y_ax_upper) / 2)
        y_ax_lower += len(c_silhouette_vals)

    silhouette_avg = np.mean(silhouette_vals)
    plt.axvline(silhouette_avg, color='red', linestyle='--')

    plt.yticks(yticks, cluster_labels + 1)
    plt.ylabel('Cluster')
    plt.xlabel('Silhouette coefficient')

    plt.show()